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171.
Male zebra finches (Taeniopygia guttata) learn to sing during a critical period in adolescence. We previously described a presynaptic protein, synelfin, whose mRNA is increased early in this critical period in a brain nucleus specifically implicated in song learning, lateral MAN (lMAN). In the current study, in situ hybridization was used to map this change in gene expression to the subregion of lMAN that projects to the robust nucleus of the archistriatum (RA), the principal motor output of the telencephalic circuit that controls song production. Using confocal immunofluorescence microscopy, we detected numerous puncta of synelfin immunoreactivity that apparently represent presynaptic terminals from lMAN in the RA of young males. Synelfin immunoreactivity in RA declined abruptly between 40 and 45 days of age, a time of major synaptic reorganization in RA. This change did not occur until about 10 days after the decline in synelfin mRNA in cell bodies within lMAN, indicating a relatively slow turnover of the protein in presynaptic terminals and suggesting that some of the functional changes that occur during the critical period may arise from regulatory decisions that were initiated a week or more earlier. Depriving birds of tutoring did not halt or delay the decline of synelfin mRNA in lMAN. This change in gene expression must not be a consequence of early song learning, but may reflect an innate or programmed step in song circuit development. 相似文献
172.
James Jaccard Donald W. Helbig Timothy B. Gage Choi K. Wan Donna C. Kritz-Silverstein Marjorie A. Gutman 《Journal of applied social psychology》1995,25(20):1765-1789
This study was an investigation of contraceptive switching in the context of a 5-wave panel design of diaphragm and pill users from the New York City metropolitan area. The respondents were 525 women between the ages of 14 and 46, who came to one of 10 family planning clinics to obtain birth control, Results indicated a hazard function for switching in which the hazard rate increased in the initial weeks and then gradually declined over time. Clinic experiences on the part of the women were found to alter survivorship trends. Implications of the data for service providers were developed. 相似文献
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Carol M. Cicerone Donald D. Hoffman Peter D. Gowdy Jin S. Kim 《Attention, perception & psychophysics》1995,57(6):761-777
We introduce and explore a color phenomenon which requires the prior perception of motion to produce a spread of color over a region defined by motion. We call this motion-induced spread of colordynamic color spreading. The perception of dynamic color spreading is yoked to the perception of apparent motion: As the ratings of perceived motion increase, the ratings of color spreading increase. The effect is most pronounced if the region defined by motion is near 1° of visual angle. As the luminance 相似文献
176.
以汉语单字词为材料,通过颜色来区分目标和分心物,采用过程分离程序,直接探讨了目标激活与分心物抑制和意识、无意识过程之间的关系。结果表明,(1)靶词充当分心物时,不仅意识过程存在的概率降低,无意识过程存在的概率也降低。这一结果说明,在选择性注意任务中,信息是有关还是无关,并不能分离意识和无意识过程;(2)靶词充当目标时,加工水平影响Pc,但不影响Pu,而靶词充当分心物时,加工水平既不影响Pc,也不影响Pu。因此,加工水平能否分离意识和无意识过程,依赖于靶词的作用或信息是否有关 相似文献
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Interrater differences in scoring actual WISC protocols were determined for three different IQ levels. In general, differences among the 94 examiners tended to be within an acceptable range as established by the SEm; varince on two Verbal subtests occasionally exceeded their corresponding SEm. Also, examiner's demographic characteristics were not a major consistent source of variance in scoring WISC protocols. 相似文献
179.
Chronic self-destructiveness: Conceptualization,measurement, and initial validation of the construct
Kathryn Kelley Donn Byrne D. P. J. Przybyla Carole Eberly Bruce Eberly Virginia Greendlinger Choi K. Wan Janet Gorsky 《Motivation and emotion》1985,9(2):135-151
Individual differences in various behaviors suggest that those who are primarily motivated by current emotional factors are more likely than those motivated by more distant cognitive considerations to engage in acts that are ultimately self-destructive. To assess and explore these behavioral differences, 12 samples of undergraduate subjects, totaling 864 (527 females, 337 males), a group of 15 businesswomen, and 111 male VA patients were used to develop a measure of this construct in a series of reliability and construct validity studies. By means of internal-consistency item analyses, two cross-validated 52-item measures of chronic self-destructiveness were constructed for males and females. Reliability was established with respect to internal consistency (alpha coefficients range from .73 to .97) and temporal consistency over a 1-month period (test-retest correlations range from .90 to .98). There is a slight drop in chronic self-destructiveness scores across age groups. Test scores were found to be positively related to external locus of control, negatively related to Type A coronary-prone behavior, and unrelated to either social desirability response set or need for achievement. Individuals high in chronic self-destructiveness, compared to those with low scores, are more likely to be in treatment for drug or alcohol abuse, to report having cheated in courses, to have had traffic violations, to report having gone through a rebellious stage in adolescence, and to postpone obtaining a medical test for cancer. Chronic self-destructiveness appears to be a personality dimension that affects behavior across a wide range of ages and situations.We wish to thank John Wapner for his assistance in obtaining data in the clinical sample. 相似文献
180.
拿到《科学无神论》(大中小学系列读本) 后,一口气将其中的小学生、中学生读本读完,然 后把小学生读本拿给上小学四年级的儿子,看到他 也深深的被书中的章节所吸引。我相信这是一套适 合孩子们阅读的、宣传科学知识的好书:一套有益 于孩子们树立正确的世界观、人生观、价值观的, 有益于他们成长的好书。 相似文献